JPH10326592A - Multiple tube type fluorescent lamp and lighting system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To fix the both ends of a glass outer tube to both ends of an arc tube in simple structure, increase airtightness, and reduce the dispersion of initial luminous characteristics and a change with the passage of time of the luminous characteristics. SOLUTION: Both ends of a glass outer tube 2 are sealed by glass melting to both ends of an arc tube 1 having a slender airtight glass bulb la, and a getter 3 is sealed onto the inside of the glass outer tube 2. The getter 3 is formed by forming a transparent thin film made of fine particles of a metal oxide such as alumina on the inner surface of the glass outer tube 2 and the outer surface of the arc tube 1, or introducing the fine particles into the glass outer tube 2 so as to be capable of flowing, or sealing a metal getter such as zirconium in the form of rod, wire, or powder. The exhausting time in sealing of the glass outer tube is shortened, the dispersion of luminous characteristics caused by the discharge of impurity gases in the initial stage of lighting is reduced, and a change with the passage of time in the luminous characteristics caused by gradual increase in pressure within the glass outer tube 2 by the impurity gases gradually discharged during life is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-tube fluorescent lamp in which a glass outer tube is provided around an arc tube, and a lighting device using the same.

[0002]

2. Description of the Related Art FIG. 12 is a sectional view of a conventional double-tube fluorescent lamp.

The above prior art is described in Japanese Utility Model Publication No. 4-52932. In the figure, 101
Is an outer tube made of glass, and 104 is a hermetically sealed envelope tube made of glass. The outer tube 101, the envelope tube 104, and holding members 106, 106 described later form a double tube structure. The outer tube 101 surrounds the envelope tube 104 such that a space S surrounding the outer wall of the envelope tube 104 is formed at an interval of about 1 to 10 mm between the inner wall of the outer tube 101 and the outer wall of the envelope tube 104, Both of them are held at both ends by heat insulating holding members 106, 106. Further, the ends 141 of the sealing tube 104 are respectively held by the holding members 10.
6 and 106, and these holding materials 1
06 and 106 are ends 111 and 11 of the outer tube 101, respectively.
1 is hermetically fitted to hermetically seal the outer tube 101, and a double tube structure is formed by the envelope tube 104, the outer tube 101, and the holding members 106, 106. It is stated that the space S is preferably reduced in pressure and evacuated, and in this case, the heat insulation between the envelope tube 104 and the outer tube 101 can be further improved. A fluorescent film 1 is provided on the inner wall surface of the envelope tube 104.
42, the total length L of the lamp is 120 mm or less, the power consumption is 2 W or less, and the outer diameter d of the envelope tube 104 is 6 mm or less. The outer diameter D of the outer tube 101 is preferably set to 20 mm or less. This double tube fluorescent lamp is used for a liquid crystal backlight or the like.

In the drawing, reference numeral 102 denotes a filament electrode, 1
03 is a lead wire and 105 is a mercury-impregnated alloy.

According to the above-mentioned prior art, power consumption is 2
Even when the temperature is less than W, since the lamp is a double tube, a required temperature rise can be obtained at the time of starting even in a relatively low-temperature atmosphere, so that the luminous flux rise is superior to that of a fluorescent lamp having no outer tube.

[0006]

However, in the prior art, it is difficult to maintain the airtightness between the outer tube and the envelope tube for a long period of time. Characteristics cannot be controlled as desired over a long period of time.

Even if airtightness can be maintained, if an impure gas such as H ₂ O, O, or H ₂ remains in the outer tube, the pressure in the outer tube does not reach the designed pressure.

Further, if the impure gas is adsorbed on the inner surface of the outer tube or the outer surface of the envelope tube, these impure gases are gradually released during the life and the pressure in the outer tube changes during the life. Become.

When the pressure in the outer tube deviates from a predetermined value, the light-emitting characteristics change because the heat insulation in the outer tube changes. When the pressure in the outer tube varies during manufacturing, there is a problem that the initial light emission characteristics vary.

When the pressure in the outer tube gradually changes during the life, the light emission characteristics change with time. In each case,
These raise significant problems with the quality of the fluorescent lamp.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a multi-tube fluorescent lamp in which the variation of the initial light emission characteristics is small and the change of the light emission characteristics with time is reduced, and an illumination device using the same.

[0012]

According to the first aspect of the present invention, there is provided a multi-tube fluorescent lamp having an elongated airtight glass bulb, a pair of electrodes sealed at both ends of the glass bulb, and an inner surface of the glass bulb. An arc tube comprising a phosphor layer and a discharge medium sealed in a glass bulb; and a space formed around and surrounding the arc tube, and both ends are sealed to both ends of a glass bulb of the arc tube. A glass outer tube; and a getter sealed in a space between the glass outer tube and the arc tube.

In the present invention and each of the following inventions, definitions and technical meanings of terms are as follows unless otherwise specified.

First, the glass bulb will be described.

The glass bulb is preferably made of hard glass such as borosilicate glass or semi-hard glass, but may be soft glass such as soda lime glass or lead glass if necessary. The cross-sectional shape is usually circular, but if necessary, it may be non-circular, for example, elliptical or any other cross-sectional shape. Further, the shape in the longitudinal direction can be a desired shape such as an annular shape, a semicircular shape, an L-shape, a U-shape, a W-shape as well as a straight pipe.

The use of the multi-tube fluorescent lamp of the present invention is not limited, since it can be applied to a fluorescent lamp for any purpose and exhibit the expected effects. Therefore, the outer diameter and the overall length of the glass bulb constituting the arc tube can be set arbitrarily. However, the present invention exerts particularly remarkable functions and effects in a relatively elongated and compact fluorescent lamp used for reading a backlight such as a liquid crystal, reading OA equipment, and illuminating an instrument mounted on a vehicle. In the case of such a relatively elongated and compact fluorescent lamp, in the present invention, the arc tube generally has an outer diameter of 6 mm.
mm or less, preferably 4 mm or less, and most preferably 3 mm or less. The wall thickness is generally 1 mm or less, preferably 0.1 to 0.7 mm, and most preferably about 0.3 mm.
Further, the overall length may be generally an arbitrary length,
Preferably 30-300 mm, optimally 50-250 m
m.

Next, the electrodes will be described.

As described above, the application of the electrode as a fluorescent lamp is not limited, and therefore, an electrode of a suitable type of a cold cathode or a hot cathode can be selected according to the application. However, when applying the present invention to a relatively elongated and compact fluorescent lamp, it is generally better to use a cold cathode, but it can be understood that the hot cathode is not excluded from the properties of the present invention. Would.

The phosphor layer will be described.

The phosphor layer may be formed directly on the inner surface of the glass bulb, or may be formed indirectly via, for example, a protective film. The phosphor to be used may be any desired one according to the application. For example, in the case of a reading fluorescent lamp, a rare earth phosphate phosphor (La) is used.
PO _4: Ce ^3+, single color emission phosphor or phosphor containing this as Tb ^3+), in the case of the backlight and multi-tube type fluorescent lamp for vehicle instrument lighting, three-wavelength emission type fluorescent material or a A phosphor having a white emission color such as a halophosphate phosphor can be used.

The discharge medium will be described.

As the discharge medium, mercury and a rare gas such as neon or argon as a main component are often used.

Further, ultraviolet rays having respective wavelengths may be generated by enclosing xenon gas and mercury to generate both xenon gas discharge and mercury vapor discharge. In this case, the problem of rising of the light beam at a low temperature can be alleviated, but the effect of improving the rising of the light beam by the multi-tube fluorescent lamp of the present invention is exhibited, and the effect of increasing the mechanical strength is added. Furthermore, if the rare gas enclosed with mercury is a simple gas of argon, neon, or krypton, or a mixed gas of argon, neon, argon, neon, and helium, startability can be improved by the Penning effect.

The mercury may directly enclose pure mercury,
It may be enclosed in the form of amalgam.

The glass outer tube will be described.

When the glass outer tube is made of glass of the same material as the glass bulb, the thermal expansion coefficient is the same, but the thermal expansion coefficient is not largely different, and the workability between the glass bulb and the glass bulb is not hindered. For example, different glass materials can be used.

As described in the description of the arc tube, since the present invention is not limited to a specific use, the glass outer tube can be set to a desired size according to the use of the fluorescent lamp. In fluorescent lamps, the glass outer tube generally has an outer diameter of 8 mm or less, preferably 6 mm or less.
mm or less, optimally 4 mm or less. The wall thickness is
Generally, 1 mm or less, preferably 0.1 to 0.7 m
m, optimally about 0.3 mm. Furthermore, the total length is
Generally, the length may be any length, but preferably 30 to
It is 300 mm, optimally 50-250 mm.

Although the glass outer tube is generally welded to the arc tube in a concentric positional relationship, it is sufficient that a gap is formed around the arc tube by the glass outer tube. No problem. In an extreme case, even if a part of the peripheral surface of the arc tube is in contact with the outer glass tube, basically the desired effect can be obtained, and this is also allowed.
In addition, even if the gap formed around the arc tube by the glass outer tube is so small that its existence can be recognized slightly, the desired operation and effect can be obtained.

In the present invention, an arbitrary number of glass outer tubes can be used, for example, concentrically. further,
The inside of the glass outer tube may be evacuated to a reduced pressure atmosphere, or the degree of vacuum may be increased to a so-called high vacuum of 100 Pa or less.

The sealing between the outer glass tube and the glass bulb of the arc tube means that both or one of the two glasses is melted and hermetically fixed, and the thermal expansion coefficient of the two is almost the same as that of the other.
It may be airtightly fixed by interposing a glass material for welding having an intermediate value between them, or may be airtightly bonded by interposing another member.

Further, the getter will be described.

In the present invention, the getter is sealed in the space between the arc tube and the glass outer tube, and adsorbs the impurity gas in the glass outer tube.

As the getter, various getters such as metal oxide fine particles such as alumina, solid phase metal such as zirconium, titanium and tantalum, and liquid phase mercury can be used.

When the metal oxide fine particles are used as a getter, a transparent film can be formed on one or both of the inner surface of the glass outer tube and the outer surface of the arc tube.

In the case where a reflection film mainly made of metal oxide particles such as alumina and / or titanium oxide is formed on the inner surface of the glass outer tube or the outer surface of the arc tube except for a light guiding slit along the tube axis. In this case, the reflective film can also function as a getter. In this case, by providing the reflection film, the tube surface luminance at the slit portion can be approximately doubled by the light collecting effect.

When a solid-phase metal getter is used, the metal getter is formed into particles or powder and is movably sealed in a glass outer tube, or is spirally wound as a metal wire over the entire length or a part of the length of the arc tube. can do. In this case, since the getter is interposed between the outer glass tube and the arc tube to suppress the vibration of the arc tube when an external impact is applied, the getter has an effect of preventing the arc tube from being damaged.

Further, a plate-shaped getter may be sealed in a glass tube.

Furthermore, in the case of liquid-phase mercury, amalgam (HgO) is formed together with O _{2 in the} impurity gas, so that it acts as a getter.

Here, an example of a method for manufacturing a double-tube fluorescent lamp will be described.

First, an arc tube is manufactured by a conventional method.

Next, the arc tube is inserted into the glass outer tube, and one end of both are supported. When the other end of the glass outer tube is heated by a gas burner, an electric heater, or the like, the glass outer tube is eventually softened, so that the other end of the arc tube and the other end of the glass outer tube can be sealed.

In this case, the glass outer tube is sealed to the sealing portion of the arc tube, that is, the sealing length of the glass outer tube to the arc tube is shorter than the sealing length of the arc tube. Sealing can be easily performed.

This is because, when the other end of the glass outer tube is firstly sealed to the other end of the arc tube, the glass outer tube is sealed in a vacuum chamber. If at least a part of the seal is straddled more centrally, it must be heated to prevent the part from being burnt, so if the part is heated, the pressure in the arc tube is relatively high, The arc tube swells and sealing failure easily occurs.

Further, when the sealing is to be performed in an inert atmosphere or a reduced atmosphere in which the pressure is higher than the inside of the arc tube, in this case as well, when the central side of the sealing portion of the arc tube is heated,
Since the pressure inside the arc tube is relatively high, the arc tube is sucked and deformed, and the glass bulb of the arc tube comes into contact with a lead wire or an electrode, causing a crack.

Now, the other end sealed by glass welding is supported, one end of the outer glass tube is connected to an exhaust device, and the entire outer glass tube is heated and evacuated in the same manner as described above to remove the impure gas. Release.

Finally, by heating one end portion while continuing the evacuation and making it the same as the other end portion, the outer glass tube surrounding the arc tube can be sealed outside the arc tube.

In general, a multi-tube fluorescent lamp can be manufactured by the above-mentioned method. A manufacturing method for further simplifying a sealing process between an outer glass tube and an arc tube will be described below.

That is, an electrode is sealed to one end of the arc tube, and one end of the arc tube and one end of the glass outer tube are sealed with the other end of the arc tube before sealing the other electrode. Seal by welding.

Next, the other end of the arc tube and the other end of the glass outer tube are separately connected to an exhaust device to exhaust air. An electrode is supported at a predetermined position in the arc tube.

Next, the discharge tube is filled with a discharge medium composed of mercury and a rare gas such as neon and argon, while the inside of the glass outer tube is brought into a high vacuum state of about 10 ^-1 Pa or, for example, xenon. Is sealed by about 100 Pa, and the other end of the glass outer tube is heated from the outside with a gas burner to seal the arc tube and the glass outer tube. In addition, mercury can be previously supported in the cylinder of the electrode as amalgam.

When the pressure inside the glass outer tube is lower than that inside the arc tube, the glass is softened and melted by heating with a gas burner.
The outer glass tube is pushed by the atmospheric pressure and is sucked inward.

On the other hand, since the arc tube has a higher pressure than the glass outer tube, it melts while expanding outward.

As a result, the outer glass tube and the arc tube are first sealed by glass welding.

When the glass outer tube and the arc tube are sealed, the inside of the arc tube is at a lower pressure than the atmospheric pressure, so that the arc tube is pushed to the atmospheric pressure, sucked and sealed.

In each of the manufacturing methods described above, the reason why the glass outer tube is filled with xenon is to prevent the lead wire of the arc tube from being oxidized and to conduct heat to the arc tube. Therefore, as the filling gas in this case,
Nitrogen may be used in addition to a rare gas such as xenon.

Further, at the one end portion to be sealed last, the glass outer tube may be sealed over the center of the arc tube from the sealing portion of the arc tube, or the center portion may be sealed. Easy to seal.

Because, when the glass outer tube is sealed to the arc tube, the pressure in the arc tube is higher than the pressure in the glass outer tube, so that when the arc tube softens, it swells outward to prevent welding with the glass outer tube. It is because it ensures. Even when the glass outer tube and the arc tube are sealed at the same time, the glass outer tube and the arc tube are sealed by sealing the glass outer tube at the end to be sealed last from the sealing portion of the arc tube. Can be reliably sealed. Moreover, when the arc tube is sealed, the bulge of the arc tube is not pushed by the atmospheric pressure,
Less.

Next, the operation of the present invention will be described.

By sealing both ends of the glass bulb and both ends of the glass outer tube, a predetermined positional relationship between the two can be securely maintained without using extraordinary members unlike the prior art. The sealing can be performed sufficiently airtight while the structure is simplified. In addition, since the mechanical strength is improved by the synergistic action of the arc tube and the outer glass tube, a relatively thin glass bulb can be used.

When the inside of the glass outer tube is set to a vacuum or a reduced-pressure atmosphere such as a rare gas, the convection action by the gas in the glass outer tube is greatly reduced or eliminated, and the rising of the luminous flux at the time of starting at a low temperature is improved by the adiabatic action. .

Further, the degassing operation will be described.

The getter enclosed in the glass outer tube contains H ₂ O adsorbed on the arc tube and / or the glass outer tube,
When impurities such as H ₂ and O ₂ are released as an impurity gas into the glass outer tube due to a rise in temperature due to lighting of the fluorescent lamp, the gas is adsorbed and degassing is performed. Therefore, the pressure inside the glass outer tube does not change due to the impurity gas.

Therefore, the pressure inside the glass tube can be maintained as designed at all times from the initial stage of lighting to throughout the life of the glass tube, so that the working characteristics are always improved.

Since the degassing can be performed by the getter function even during the evacuation in the manufacturing process in the outer glass tube, the degree of vacuum of the glass tube can be increased. For this reason, manufacturing variations can be reduced, and the evacuation time can be shortened.

Further, in order to effectively perform degassing in the process of manufacturing the fluorescent lamp, one end of the glass outer tube is sealed to the light emitting tube, the other end of the glass outer tube is connected to an exhaust device, and the rare gas is exhausted. Appropriate pressure such as atmospheric pressure to 10 Pa
After filling into the glass outer tube to the extent, it is heated in an exhaust furnace. Then, not only the glass outer tube but also the arc tube heats up satisfactorily due to the heat conduction action of the rare gas, so that the degassing of the inner surface of the glass outer tube and the outer surface of the arc tube is performed well.

On the other hand, when the inside of the glass outer tube is only evacuated, the inside of the glass outer tube has a high vacuum up to about 10 ^-1 Pa, so that the space in the glass outer tube performs a heat insulating action, Since the temperature of the outer surface does not rise as desired, not only degassing, but also sealing of the arc tube and the glass outer tube by glass welding is hindered.

In order to perform degassing more effectively, it is preferable to fill the glass outer tube with a rare gas at least once in an exhaust furnace. In this case, better degassing can be performed by the washing effect from the temperature difference between the sealed rare gas and the outer surface of the arc tube.

The multi-tube fluorescent lamp according to the second aspect of the present invention,
2. The multi-tube fluorescent lamp according to claim 1, wherein the getter is attached to an inner surface of the outer glass tube.

In the present invention, since the getter is adhered to the inner surface of the glass outer tube, it is desirable that the getter does not undesirably lower the light transmittance of the glass outer tube. In this regard,
Particle diameter of a transparent metal oxide such as alumina is 0.4-0.
A thin film composed of fine particles of about 5 μm has good transparency and is therefore suitable as a getter in the present invention. Getters composed of fine particles of metal oxides such as alumina
Getter action is performed by the physical adsorption effect by the intermolecular adsorption force of Van der Waals.

The getter may be formed on the entire inner surface of the glass outer tube or may be formed partially.

The multi-tube fluorescent lamp according to the third aspect of the present invention comprises:
The multi-tube fluorescent lamp according to claim 1 or 2,
The getter is characterized in that it is attached to the outer surface of the arc tube.

The present invention is also the same as the second aspect. However, the getter allows the getter to be attached to both the inner surface of the glass outer tube and the outer surface of the arc tube.

The multi-tube fluorescent lamp according to the invention of claim 4 is:
4. The multi-tube fluorescent lamp according to claim 1, wherein the getter is movably sealed.

As the getter, if the metal oxide fine particles are directly introduced into the glass tube in a powder state, or if the metal is formed into particles and introduced, the getter can be movably sealed in the outer glass tube. .

Thus, in the present invention, since the getter is movably sealed, no special means for supporting the getter at a predetermined position is required, so that the structure is simple.

The multi-tube fluorescent lamp according to the invention of claim 5 is
The multi-tube fluorescent lamp according to any one of claims 1 to 4, wherein one end of the glass outer tube is sealed to a sealing portion of the arc tube, and the other end is sealed closer to the center than the sealing portion of the arc tube. It is characterized by being worn.

In the present invention, the expression that the glass outer tube is sealed to the sealing portion of the arc tube means that the sealing of the glass outer tube to the arc tube is regarded as being performed at the sealing portion of the arc tube. is there. Therefore, the axial length of the sealing portion of the glass outer tube to the arc tube is shorter than the axial length of the sealing portion of the arc tube.

Further, that the glass outer tube is sealed to the center side of the sealed portion of the arc tube means that the glass outer tube is sealed over the sealed portion of the arc tube and the portion on the center side thereof. Or sealed only at the center of the arc tube. In the former case, the axial length of the sealing portion of the outer glass tube is larger than the axial length of the sealing portion of the arc tube. In the latter case, the axial length of the sealing portion of the outer glass tube may be longer or shorter than that of the arc tube.

According to the present invention, the structure in which the outer glass tube is sealed to the sealing portion of the arc tube is suitable for the first sealing, as mentioned in the description of the manufacturing method of claim 1. The configuration in which the sealing is performed at the center side of the sealing portion of the arc tube is suitable when the sealing is performed last.

The multi-tube fluorescent lamp according to the invention of claim 6 is:
The multi-tube fluorescent lamp according to any one of claims 1 to 5, wherein the arc tube has an outer diameter of 6 mm or less and a wall thickness of 1 mm.
The outer diameter of the glass outer tube is 8 mm or less and the wall thickness is 1
mm or less;

The present invention defines the size of a general arc tube and a glass outer tube as an elongated and compact fluorescent lamp which is used for a backlight such as a liquid crystal, reading, and illumination of a vehicle instrument.

A multi-tube fluorescent lamp according to the invention of claim 7 is
7. The multi-tube fluorescent lamp according to claim 1, wherein the arc tube has an outer diameter of 4 mm or less and a wall thickness of 0.1 mm.
1 to 0.7 mm, total length is 30 to 300 mm; glass outer tube has outer diameter of 6 mm or less and wall thickness of 0.1 to 0.7 m
m, the total length is 30 to 300 mm;

The present invention defines a more preferable range as compared with claim 6.

According to an eighth aspect of the present invention, there is provided a lighting apparatus main body; and a multi-tube fluorescent lamp according to any one of the first to seventh aspects provided in the lighting apparatus main body. I have.

The illumination device of the present invention is not limited in its use for the same reason that the multiple tube fluorescent lamp in the preceding claim is not limited in its application as described above. For example, it includes lighting equipment for general lighting. However, when an elongated and compact multi-tube fluorescent lamp is used, a lighting device for general lighting may be used, but a backlight device such as a liquid crystal device, an image reading device for an image forming device, and a lighting device for a vehicle-mounted instrument. To adapt to.

[0086]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a partially cutaway schematic front view showing a first embodiment of a multi-tube fluorescent lamp according to the present invention.

FIG. 2 is an enlarged cross-sectional view of the main part.

In the figure, 1 is an arc tube, 2 is a glass outer tube, and 3 is a getter.

The arc tube 1 is an elongated airtight glass bulb 1
a, a pair of cold cathode type electrodes 1b sealed inside both ends of a glass bulb 1a, a lead wire 1c supporting the electrode 1b and extending through an end of the glass bulb 1a, an inner surface of the glass bulb 1a. The discharge layer is formed of a rare gas mainly composed of mercury and argon as a discharge medium sealed in the phosphor layer 1d and the glass bulb 1a. The arc tube 1
The glass bulb 1a has an outer diameter of 2.4 mm and a wall thickness of 0.3 mm.

The outer glass tube 2 has an outer diameter of 3.6 mm and a thickness of 0.3 mm, and both ends thereof are fused to both ends of the glass bulb 1a of the luminous tube 1 in a concentric positional relationship with the luminous tube 1a. Sealed by.

The getter 3 is made of a transparent thin film of alumina fine particles, and is formed on almost the entire inner surface of the glass outer tube 2.

The total length of the obtained multi-tube fluorescent lamp is 200 mm.

FIG. 3 is an enlarged sectional view of a main part showing a second embodiment of the multi-tube fluorescent lamp of the present invention.

In the figure, the same parts as those in FIG.

The present embodiment differs from the first embodiment of the multiple tube fluorescent lamp of the present invention in that the getter 3 is formed on almost the entire outer surface of the arc tube 1.

FIG. 4 is an enlarged sectional view of a main part showing a third embodiment of a multi-tube fluorescent lamp according to the present invention.

In the figure, the same parts as those in FIG.

The present embodiment differs from the first embodiment of the multi-tube fluorescent lamp of the present invention in that the getter 3 is formed on almost the entire outer surface of the arc tube 1 and the inner surface of the glass outer tube.

FIG. 5 is a partially cut-away enlarged sectional view showing a fourth embodiment of a multi-tube fluorescent lamp according to the present invention.

In the figure, the same parts as those in FIG.

The present embodiment is characterized in that the structure of the sealing portion of the outer glass tube to the arc tube is different between one end and the other end.

Sealing part A at the left end of the glass outer tube 2 in the drawing
Are formed on the sealing portion 1e of the arc tube 1. Therefore, the length of the sealing portion A in the tube axis direction is equal to the length of the sealing portion 1 of the arc tube 1.
It is shorter than the length of e.

On the other hand, the sealing portion B on the right side of the glass outer tube 2 in the drawing is sealed from the sealing portion 1e of the arc tube 1 to the center. Therefore, the length of the sealing portion B in the tube axis direction is larger than the length of the sealing portion 1 e of the arc tube 1.

The present invention is suitable when the sealing portion A is sealed first and the sealing portion B is sealed last.

FIG. 6 is a conceptual diagram of an exhaust device showing a manufacturing process of a fifth embodiment of a multi-tube fluorescent lamp according to the present invention.

In the figure, the same parts as those in FIG. 2 are denoted by the same reference numerals, and description thereof will be omitted.

4 is an exhaust head, 5, 6, 7, and 8 are valves, 9 is a rotary pump, 10 is a diffusion pump, 11 is a gas cylinder, and 12 is a pipe.

The arc tube 1 is manufactured in advance, and one end of the glass outer tube 2 is sealed to one end of the arc tube 1 by glass welding. The other end of the outer glass tube 2 is provided with an extension 2 a for sealing while being connected to the exhaust head 4.

The exhaust head 4 is provided with an extension 2 of the glass outer tube 2.
a. Initially, valves 5 and 7 are opened and valve 6
And 8 are closed, and the exhaust head 4 is connected to the rotary pump 9 to evacuate the inside of the glass outer tube 2 to a pressure of about 10 ^-1 Pa. Further, when a high vacuum is required, the valve 7 is closed,
The valve 6 is opened to switch from the rotary pump 9 to the diffusion pump 10 to further exhaust air.

Next, the valve 8 is opened with the valves 5 to 7 closed, and xenon is filled into the outer glass tube 2 from the gas cylinder 11 via the pipe 12 so as to have a pressure of about 100 Pa.

Then, it is put into the exhaust furnace shown in FIG.

FIG. 7 is a conceptual diagram of an exhaust furnace showing a manufacturing process of a fifth embodiment of the multi-tube fluorescent lamp of the present invention.

In the figure, the same parts as those in FIG.

Reference numeral 13 denotes an exhaust furnace, which is configured to be able to exhaust while heating.

In FIG. 6, when the glass outer tube 2 is filled with xenon in the exhaust furnace 13 and the temperature inside the furnace is increased, the glass outer tube is heated to increase the temperature and the xenon gas , And the arc tube 1 is also heated to increase the temperature.

Therefore, the impurity gas adsorbed on the inner surface of the glass outer tube 2 and the outer surface of the arc tube 1 is released. The released impurity gas is absorbed by the getter 3 and
By exhausting air through the exhaust head 4, sufficient degassing can be performed.

However, if further degassing is desired, xenon is evacuated in the exhaust furnace 13 and then filled with xenon at least once. Thus, degassing can be further promoted by the washing action.

FIG. 8 is a conceptual diagram of an exhaust device showing a manufacturing process of a sixth embodiment of a multi-tube fluorescent lamp according to the present invention.

In the figure, the same parts as those in FIG.

This embodiment is different from the fifth embodiment of the multi-tube fluorescent lamp of the present invention shown in FIG. 6 in that the other ends of the arc tube 1 and the outer glass tube 2 are simultaneously sealed.

One end of each of the arc tube 1 and the glass outer tube 2 is sealed in advance by glass welding, and the other end is provided with an extension 1f to be opened. The extension 1f at the other end of the arc tube 1 is connected to the exhaust head 4a, and the extension 2a at the other end of the outer glass tube 2 is connected to the exhaust head 4b.

The exhaust head 4a is connected to the pump 14 via the pipe 12a, the valve 15 and the valve 7, and
And a gas cylinder 17 via a valve 16.
The gas cylinder 17 stores a rare gas as a discharge medium such as argon. Note that the pump 14 is configured to be able to switch between a rotary pump and a diffusion pump.

The exhaust head 4b is connected to the pump 14 via the pipe 12b and the valves 5 and 7, and is connected to the gas cylinder 11 via the pipe 12b and the valve 8.

When the arc tube 1 and the glass outer tube 2 are sealed, the valves 5, 7 and 15 are opened, and the inside of the arc tube 1 and the glass outer tube 2 is evacuated as required by the pump 14.

After exhausting, the valve 15 is closed and the valve 16 is opened, and a rare gas for a discharge medium such as argon is filled at a predetermined pressure. The mercury is stored in advance in the cylinder of the electrode 1b in the form of amalgam.

On the other hand, with respect to the outer glass tube 2, the valve 5 is closed and the valve 8 is opened to fill the gas cylinder 11 with xenon at a predetermined pressure.

The xenon pressure in the outer glass tube 2 is
It should be lower than the gas pressure inside.

Then, at the position where the other end is to be sealed, the gas outer tube 2 and the arc tube 1
Is heated to seal the other end. Further details are shown in FIG.
It will be described based on.

FIG. 9 is an enlarged sectional view of a main part showing a sealing step in a sixth embodiment of the multi-tube fluorescent lamp of the present invention.

In the figure, the same parts as those in FIG. 2 are denoted by the same reference numerals, and description thereof will be omitted.

The electrode 1b is sealed to the bead stem 1e, and is suspended by a support (not shown). The gap required for exhaust and gas filling is formed between the bead stem 1e and the inner surface of the glass bulb 1a of the arc tube 1.

Then, as explained in FIG.
In a state in which the arc tube 1 and the glass outer tube 2 are filled with the respective gases, as shown in FIG. The outer glass tube 2 is heated in the G direction.

When heated by a gas burner, the temperature of the glass outer tube 2 rises, and the temperature of the arc tube 1 also rises due to heat conduction through xenon.

Eventually, the glass outer tube 2 and the arc tube 1 soften and melt.

Then, as shown in FIG. 9B, the molten portion of the glass outer tube 2 is sucked by being pressed by the atmospheric pressure.

On the other hand, the molten portion of the arc tube 1 swells because the pressure inside the arc tube 1 is higher than that inside the glass outer tube 1.

As a result, the fused portions of the outer glass tube 2 and the arc tube 1 are fused to each other.

When the outer glass tube 2 and the arc tube 1 are fused, as shown in FIG. 9C, the arc tube 1 is pushed by the atmospheric pressure and sucked in due to the difference between the atmospheric pressure and the pressure in the arc tube. Then, the other end of the arc tube 1 is sealed. After sealing, the extension parts 1f and 2a of the arc tube 1 and the glass outer tube 2 are blown off by a gas burner, and then gradually cooled, the sealing by glass welding is completed.

FIG. 10 is an exploded perspective view of a liquid crystal display device for an in-vehicle instrument, showing a first embodiment of the lighting device of the present invention.

In the figure, 18 is a backlight unit, 19 is a liquid crystal display unit, and 20 is a display device.

The backlight unit 18 supports the light guide 18a made of acrylic resin, the multi-tube fluorescent lamp 18b and the multi-tube fluorescent lamp 18b arranged on the side of the light guide 18a, and surrounds the reflecting lamp. It is composed of a plate 18c and the like.

The liquid crystal display unit 19 is provided on the front of the backlight unit 18.

Thus, the backlight unit 18 and the liquid crystal display unit 19 constitute a liquid crystal display device 20 for a vehicle instrument.

The operation of the backlight unit 18 and the liquid crystal display device 20 is essentially the same as that of the backlight unit using a single tube fluorescent lamp even when the multi-tube fluorescent lamp 4b is used as a light source. Description is omitted because it is well known.

FIG. 11 is a conceptual sectional view of a reading device showing a second embodiment of the illumination device of the present invention.

In the figure, reference numeral 21 denotes a reading device, which is a multi-tube fluorescent lamp 21a, a light receiving means 21b, and a signal processing device 21.
c, a document placing surface 21d, a reflecting mirror 21e, and a case 21f for accommodating each of the above components.

The reader is applicable to OA equipment such as a copying machine, an image scanner, and a facsimile.

The operation of the reading device is essentially the same as that of a reading device using a single tube fluorescent lamp even if the multi-tube fluorescent lamp 21a is used as a light source.

[0150]

According to the first to seventh aspects of the present invention, both ends of the glass outer tube surrounding the arc tube are sealed to both ends of the arc tube, and a getter is sealed in the glass outer tube. In addition, it is possible to provide a multi-tube fluorescent lamp in which variations in initial light emission characteristics are reduced and / or changes in light emission characteristics with time are reduced.

According to the second aspect of the present invention, it is possible to provide a multi-tube fluorescent lamp in which a getter is attached to the inner surface of a glass outer tube.

According to the third aspect of the present invention, it is possible to provide a multi-tube fluorescent lamp in which a getter is attached to the outer surface of the arc tube.

According to the fourth aspect of the present invention, in addition, since the getter is movably sealed, a multi-tube fluorescent lamp having a simple structure can be provided.

According to the invention of claim 5, in addition, one end of the glass outer tube is sealed to the sealing portion of the arc tube, and the other end is sealed to the center side from the sealing portion of the arc tube. It is possible to provide a multi-tube fluorescent lamp that has good sealing and is easy to manufacture.

According to the sixth aspect of the present invention, it is possible to provide a multi-tube fluorescent lamp in which the sizes of a general arc tube and a glass outer tube are specified for an elongated and compact lighting device.

According to the seventh aspect of the present invention, it is possible to provide a multi-tube fluorescent lamp in which the sizes of the arc tube and the glass outer tube which are preferable for an elongated and compact lighting device are defined.

According to the invention of claim 8, it is possible to provide a lighting device having the effects of claims 1 to 7.

[Brief description of the drawings]

FIG. 1 is a partially cut-away schematic front view showing a first embodiment of a multi-tube fluorescent lamp of the present invention.

FIG. 2 is an enlarged sectional view of a main part of the same.

FIG. 3 is an enlarged sectional view of a main part showing a second embodiment of the multi-tube fluorescent lamp of the present invention.

FIG. 4 is an enlarged sectional view of a main part showing a third embodiment of the multi-tube fluorescent lamp of the present invention.

FIG. 5 is a partially cutaway enlarged sectional view showing a fourth embodiment of the multi-tube fluorescent lamp of the present invention.

FIG. 6 is a conceptual diagram of an exhaust device showing a manufacturing process of a fifth embodiment of a multi-tube fluorescent lamp according to the present invention.

FIG. 7 is a conceptual diagram of an exhaust furnace showing a manufacturing process of a fifth embodiment of the multi-tube fluorescent lamp of the present invention.

FIG. 8 is a conceptual diagram of an exhaust device showing a manufacturing process of a sixth embodiment of the multi-tube fluorescent lamp of the present invention.

FIG. 9 is an enlarged sectional view of a main part showing a sealing step in a sixth embodiment of the multi-tube fluorescent lamp of the present invention.

FIG. 10 is an exploded perspective view of a liquid crystal display device for an in-vehicle instrument, showing a lighting device according to a first embodiment of the present invention.

FIG. 11 is a conceptual sectional view of a reading device showing a second embodiment of the illumination device of the present invention.

FIG. 12 is a cross-sectional view of a conventional double-tube fluorescent lamp.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Arc tube 1a ... Glass bulb 1b ... Electrode 1c ... Lead wire 1d ... Phosphor layer 2 ... Glass outer tube 3 ... Getter

Claims (8)

[Claims] An elongated airtight glass bulb, a pair of electrodes sealed at both ends of the glass bulb, a phosphor layer formed on an inner surface side of the glass bulb, and a discharge medium sealed in the glass bulb. An arc tube; a glass outer tube surrounding the arc tube with a gap formed therearound and sealed at both ends to both ends of a glass bulb of the arc tube; and in a space between the glass outer tube and the arc tube. And a sealed getter. 2. The multi-tube fluorescent lamp according to claim 1, wherein the getter is attached to an inner surface of the outer glass tube. 3. The multi-tube fluorescent lamp according to claim 1, wherein the getter is attached to an outer surface of the arc tube. 4. The multi-tube fluorescent lamp according to claim 1, wherein the getter is movably sealed. 5. The glass outer tube has one end sealed to a sealing portion of the arc tube and the other end sealed to a center side of the sealing portion of the arc tube. 5. The multi-tube fluorescent lamp according to any one of 4. 6. The arc tube has an outer diameter of 6 mm or less and a thickness of 1 mm.
The outer diameter of the glass outer tube is 8 mm or less and the wall thickness is 1
mm or less; the multi-tube fluorescent lamp according to any one of claims 1 to 5. 7. An arc tube having an outer diameter of 4 mm or less and a wall thickness of 0.1 mm.
1 to 0.7 mm, total length is 30 to 300 mm; glass outer tube has outer diameter of 6 mm or less and wall thickness of 0.1 to 0.7 m
7. The multi-tube fluorescent lamp according to any one of claims 1 to 6, wherein m is 30 to 300 mm in total length. 8. A lighting device comprising: a lighting device main body; and the multi-tube fluorescent lamp according to claim 1 disposed in the lighting device main body.